The west sandy land of the Northeast China Plain is located in the eastern huge sandy belt of mid-latitude in Eurasia and the eastern fringe of desertified land with best bio-climatic conditions in China. With rapid e...The west sandy land of the Northeast China Plain is located in the eastern huge sandy belt of mid-latitude in Eurasia and the eastern fringe of desertified land with best bio-climatic conditions in China. With rapid economic development, the deterioration of eco-environment has occurred and the desertification becomes very obvious. The first part of this paper studies the regional differences of landscape patterns and explores the regional differences of desertification. The second part aims to reveal the dynamics of desertification in the 1990s by using NOAA/AVHRR data and thematic data in GIS database. This work lays a scientific basis for the rehabilitation and development of the sandy lands.展开更多
Based on the analyses of grouped activity features of deep-focus (M≥6.0) and shallow-focus (M S≥5.0) earthquakes in the Northeast China region, the time-space correlation between deep focus “strong earthquake group...Based on the analyses of grouped activity features of deep-focus (M≥6.0) and shallow-focus (M S≥5.0) earthquakes in the Northeast China region, the time-space correlation between deep focus “strong earthquake group" and shallow focus “strong earthquake group" have been studied. The study was mainly on the characteristics of earthquake distribution on the collision zone between the west Pacific plate and the Eurasian plate and on its relations to the morphological feature of the western Pacific subduction zone. Moreover, emphasis was laid on analysis of the effect of the west Pacific plate on the seismicity of Eurasian plate. It is shown that in the region where the west Pacific plate subducts at low angles, the seismicity on the plate collision zone is strong, the effect of plate subduction on Eurasian continent is strong too, and the subduction zone is under a state of high compressional stress. However, in the region where the west Pacific plate subducts at high angles, the seismicity along the plate collision zone is weak, the effect of plate subduction on Eurasian continent is weak too, and the tensile stress produced by the subduction zone at depth is enhanced. We therefore propose that the seismicity in the northeast China region will enter an active period of shallow “strong earthquake group" in the future 10 years. In the period, six earthquakes of M S≥5.0 may occur. Therefore, the work of earthquake monitoring and prediction in this region shall be strengthened.展开更多
文摘The west sandy land of the Northeast China Plain is located in the eastern huge sandy belt of mid-latitude in Eurasia and the eastern fringe of desertified land with best bio-climatic conditions in China. With rapid economic development, the deterioration of eco-environment has occurred and the desertification becomes very obvious. The first part of this paper studies the regional differences of landscape patterns and explores the regional differences of desertification. The second part aims to reveal the dynamics of desertification in the 1990s by using NOAA/AVHRR data and thematic data in GIS database. This work lays a scientific basis for the rehabilitation and development of the sandy lands.
文摘Based on the analyses of grouped activity features of deep-focus (M≥6.0) and shallow-focus (M S≥5.0) earthquakes in the Northeast China region, the time-space correlation between deep focus “strong earthquake group" and shallow focus “strong earthquake group" have been studied. The study was mainly on the characteristics of earthquake distribution on the collision zone between the west Pacific plate and the Eurasian plate and on its relations to the morphological feature of the western Pacific subduction zone. Moreover, emphasis was laid on analysis of the effect of the west Pacific plate on the seismicity of Eurasian plate. It is shown that in the region where the west Pacific plate subducts at low angles, the seismicity on the plate collision zone is strong, the effect of plate subduction on Eurasian continent is strong too, and the subduction zone is under a state of high compressional stress. However, in the region where the west Pacific plate subducts at high angles, the seismicity along the plate collision zone is weak, the effect of plate subduction on Eurasian continent is weak too, and the tensile stress produced by the subduction zone at depth is enhanced. We therefore propose that the seismicity in the northeast China region will enter an active period of shallow “strong earthquake group" in the future 10 years. In the period, six earthquakes of M S≥5.0 may occur. Therefore, the work of earthquake monitoring and prediction in this region shall be strengthened.
